A wind turbine comprises a rotor that is connected to a nacelle. The nacelle arranged on top of a tower, and the tower is connected to a foundation.
To install a wind turbine, the wind turbine is transported in several parts to the installation site.
At the installation site the tower is connected to the foundation and thereafter the nacelle and the rotor are installed on top of the tower.
The tower often comprises several segments that are connected to form the tower.
Wind turbines are installed onshore and offshore. Offshore wind turbines are installed on a monopole or a tripod, for example. The parts of the wind turbine are transported to the offshore installation site by ship.
The tower of an offshore wind turbine is stored on the ship in an upright position.
Wind acts on the tower during transportation and installation. The wind induces vibrations into the tower. The above-indicated vibrations are commonly called vortex induced vibrations (VIV) which can be the result of alternating vortex shedding around the tower in strong wind conditions. This shedding results in alternating pressure differences over the wind turbine tower's cross-section. These vibrations can damage the tower and disturb the installation work in progress.
Several measures are known to dampen the vibrations. It is known to install vibration absorption components at the tower.
CN 29121154817 A1 discloses a tower drum, and further provides a wind generating set containing the tower drum. The tower drum comprises a tower drum body used for supporting a wind driven generator. A vibration absorption component used for reducing transverse vibration of the tower drum body is arranged on the peripheral surface of the tower drum body.
KR 20090102396 A describes a device for damping vibration which is caused of the vortex of an aero-generator tower, that is provided to extend the service life by reducing the vibration of the aero-generator by mounting a vortex reducing member to the tower.
US 2009019791 A1 describes a tool for preventing the vortex effect, comprising three corrugated tubes which extend helically from the upper end (2) of the tower (3), such as to cover only the upper part thereof.
The described detachable strakes are installed at the tower of the wind turbine before the tower is shipped to the installation site. After the installation, the strakes are detached from the wind turbine, and they need to be stored and transported. The handling of the strakes can become difficult.